If you import a script from another program (or you have rebuilt a damaged Final Draft file) and you find that, for example, you have scene headings that are formatted as action or character names that are formatted as dialogue, you can easily get these pieces of text looking the way they're supposed to look.
There are two ways to do this: If you only have mis-formatted text here and there, simply put the blinking cursor in a paragraph that needs to be reformatted -- no need to highlight the whole thing -- and choose the correct element from the Elements drop-down menu. In FD10 / 9 / 8 for Mac this is at the bottom left of the screen and on Windows and on Mac FD 7 / 6 / 5 it's at the top center.
If you have lots of reformatting to do, go to Tools > Reformat and a new toolbar will pop up (you may want to drag it to a corner of your screen so you can see your page). The Reformat tool will highlight a block of text and allow you, by choosing the right element, to correct the format of that block of text. In the example below, you would choose (5) Dialogue to convert "I'm a big girl." from Action to Dialogue. The Reformat tool will move on to the next block of text and you can reformat it, skip over it or delete it.
NOTE: The Reformat tool can't break up blocks of text, so if you have scene headings, action, character names and/or dialogue all clumped together in one paragraph, you will first need to do a pass separating these sections of text. Use the Enter / Return key to place each individual paragraph on its own line. Then use the Reformat tool.
It should take about 45-60 minutes to reformat an entire feature-length script.